Economizer unit for carburetors



Patented Mar. 17, 1953 UNITED STATES l"PATENT vOFFICE 'jThis invention relates tocarburetors for internal combustion engines, and more particularly to an economizer mechanism or :device to enable lthe carburetor to supplyfuel to the engine in 'increased quantity to increasethe power there- ,of when needed.

Most carburetors .as now'constructedinclude a f device, usuallyreferredto as lan'economizer or .power jet, which includesxa valve controlled by a piston or diaphragm subjected'to the vacuum the intake manifold "toincreaserthe rate of `fuel vsupply` to the carburetor, and thereby enrich the fuel-air mixture, when the throttle is in or near its`fully open position. Such devices .are often subject to leakage, which Vmay result in `drawing. excess fuel into the induction passage at .times Vwhen it is not wanted, thereby unduly'en- .riching the mixture, with loss ofgasoline'econ- ,omy. Leakage through the economizer may re- ,sult from defective operationof vthe economizer valve, either becauseof wear due to vibration or ".Defective operation of the economizer may also result from a defective or maladjusted valve spring. Thus, if the economizer valve is designed to. open at a suction inthe manifold: of, say, seven .inches of mercury, it may open at a lowerora higher suction, causing' either a wastelof fuelor Vfaulty operation` of the engine.

Defective operationof the economizer may also Vresult from leakage of the fuel through the economizer, .which mayresultA in draining the float chamber bygravity while the car-,is standing with 'the engineA not in operation.

Defective operation of the economizer may retsultfrom various other causes, and is difficult to ldetect, since commercial carburetors are so constructed that it is impossible, Without dis- -assembling the carburetor, to apply a measured amount of suction to the fueloutlet thereof and to the vacuum connection, and measure ther re- '."sulting fuel ow. Also if leakage is found or suspected, it is difficult to remedy by means of ordinaryshop tools.

-An objectof the present invention is to vprovide -a carburetor comprising an economizer mechanism having improved means for preventing leakageof fuel therethrough.

A further object of thev invention .islto Yprovide an economizer wherein the valveisreadilyrevplaceable and which will not often ,getout of Aproper working order.

A`further object of the'invention isv to provide a carburetor wherein the -economizerv unitmay because corrosion or the presence of foreign mat- -ter such as grit prevents it fromseating. properly.

readily oe withdrawn for testing, cleaning and adjustment, and replaced Awithout valtering its adjustment.

A further object Aof the invention is to provide Veconomizer'mechanismv which is usablel in known types of carburetors in substitutionfor the corresponding mecharn'sm originally supplied with the carburetor.

The invention comprisesv an economizer ofthe diaphragm type` including ashellv or body which, with its "contained elements,V may be Vremoved as a unit, tested by applying suction thereto, ad-

vjusted by means of' suitable tools, and replaced in the carburetor'without 'disassembling the unit or disturbing the adjustment. ."Leakage between relativ-ely moving parts of the unit is prevented by sealing members of the type disclosed in -my copendinCr application: Serial No. 83,688,'filed March 26, 1949, such membersproviding a yielding and relatively irictionless yet fluid-tight'seal between the parts.

Further objects and advantages of the invention will be `apparent from the following description, taken in 'connection with the appended drawings, in which:

Figl is a diagrammatic view of'a'carburetor A'and the fuel system thereof showingyon `anzenlarged scale, -the device of thepresent invention incorporated therein, withl the' economizer'valve in closedposition.

Fig. 2 is an enlarged sectional'view of the `economizer unit and its associated parts, showing the economizer valve in openposition.

Fig. 3- is a' perspective View showing vrthe economizer-valve `embodying the vpresent invention, separately.

It is to be understood that the invention is not limited in its application to the details of construction and arrangementof vparts illustrated in the accompanying drawings, ysince the invention is capable of other embodimentsand of being practiced or carried out in various ways. 'Also it is to be understood thatthe'rphraseology or terminology employed herein is forV thejpurpose of description and noty of limitation.

The carburetor shown in the drawing is ofthe v"downdraft' type'commonly usedwithautomobile engines, but may be of anygkno-Wn or suitable construction. It'comprises a body'forming an rvan internalcombustion engine, not shown. `..The

55 ,induction passage iscontrolledin thegusual manner'ioy a manually operated 'throttle valve"l`6.

' disk 60 having a central aperture 62.

Usually an air cleaner, such as is indicated fragmentarily at I8, is connected to the air inlet.

Fuel is supplied to the induction passage from a reservoir 20, which in the example shown is a float chamber having a float 22 therein, which actuates a fuel valve 24 controlling a fuel inlet 26 leading from any suitable source of supply. Thence the fuel ilows through passages 28, 30 to the main fuel nozzle 32, which discharges at the throat of the main venturi I2. In the example shown, a second venturi 84 is provided to form a discharge member for the main nozzle. A metering orifice 86 is provided in the passage 28, as

is the usual practice, and an idling fuel passage 38 of any suitable construction may lead from the passage 30 to a point above the fuel level L and discharge adjacent the edge of the throttle |6 when the same is in closed position. Suitable acceleration pump mechanism, as well as check valves, vents, and metering orifices may be provided, as known in the art.

The economizer constituting the present invention comprises a body or shell having a threaded portion 46 which is screwed into a threaded bore in the bottom 48 of the float charnber so that the entire unit may readily be removed from the carburetor. The bottom 48 cooperates with a cover plate 50, secured thereto by bolts to form a vacuum chamber 52 which is connected by a vacuum passage 54 to the induction passage of the carburetor at a point posterior to the throttle |6.

The lower portion of the economizer body is flared to form a recessed base 56 the lower edge 58 of which is spun inwardly to retain a cupped A flexible diaphragm 64 has its edges clamped between members 56 and 60 and is subjected on its underside to the vacuum in the induction passage posterior to the throttle. diaphragm 64 forms a chamber 65. The diaphragm 64 is preferably formed of neoprene, an elastomer which is highly resistant to gasoline and to the acids and other impurities contained therein.

The diaphragm is connected by any suitable coupling 66 to a plunger 68 which is reciprocable within a septum formed in base 56 of the economizer body. The upper reduced end of the plunger constitutes a stem 12 which is designed to actuate a retaining member 74 forming part of the movable member of the economizer valve, to raise it ofl its seat when the manifold vacuum is low, as shown in Fig. 2, and to close it when the manifold vacuum is high, as shown in Fig. l.

A recessed collar 16 is adjustably fixed to an intermediate portion of plunger 68, as by a driven fit, and forms a seat for a compression spring 78 which urges the plunger upwardly, the lower end of the spring being seated against septum 70. The bottom wall 48 of the cat chamber is formed with an annular recess 80 which communicates with radial ports 8| formed in the portion 45 of the economizer, and thence with an outlet passage 82 which is connected to passage 30 by a metering orice 83.

A tubular member 84 forms the upper portion of the economizer body, and has an externally threaded sleeve 85 which is threaded into the upper end of the portion 46, leakage between the two being prevented by a gasket 85. A bored plug 88 is threaded into the upper end of the member 84, and a retaining plug 89 is driven into the bore of plug 88, to serve as an adjustable seat for a light compression spring 90 which' bears against The space above the ,1

4 the retaining member 14 to urge the same toward its seat 92.

Radial ports 94 connect the iioat chamber 20 tothe interior of the economizer body, whence fuel ows through a port 96 to the fuel space 95 within member 84, past the collar 16, and thence through ports 8|, passage 82, and orice 83 to the main nozzle 32. Plug 89 is provided with a relief port 98 which connects with the interior of the float chamber, to permit the member 14 to move freely.

The retaining member 'I4 is of circular form, and has a projection 99 at its top to provide a seat for the spring 90. An axial bore in member 74 receives the stem 12 in loose fitting relation to form a one-way rockable connection therewith. 'Ihe member 14 has a depending flange |00 which embraces the stem 'I2 and is spun outwardly to retain an annular washer |02, which acts to contact the shoulder of the seat 92 and to be deformed thereby when the valve is closed. The washer |02 thus forms with the retaining member 'i4 a valve element which, when manifold vacuum causes stem 12 to move downwardly, is moved by spring 90 into Contact with the valve seat 92 surrounding the port 96, to thereby obstruct the iiow of fuel as indicated in Fig. 1. At lower vacuum, the member 14 is moved by spring i8 to the position indicated in Fig. 2, to permit an auxiliary flow of fuel through port 96 and thence to the carburetor.

Suicient clearance is provided between plunger 68 and septum 'I0 to permit free movement of the plunger. In order to prevent leakage of fuel downwardly from the space to the chamber 65 above the diaphragm 64 during the time when the economizer valve is open, such as when the engine is operating with a nearly open throttle or when the engine is still, an annular sealing member or O-ring |03 is tted about a collar |84 on the plunger, in such relation that when the plunger is in its uppermost position, the sealing member is deformed slightly as indicated in Fig. 2 and acts to prevent flow of fuel from the space 95 to the chamber 65. The member |93, as well as the washer |02. is of the type disclosed in applicants copending application Serial No. 83,688, led March 26, 1949, being of circular cross section and made of material which is capable of elastic distortion under the pressures to which it is subjected, and impervious and resistant to gasoline and to the acids and other impurities contained in commercial gasoline. An example of a material which is satisfactory is Buna N, which has also a low coeiiicient of friction to metal in the presence of gasoline.

The economizer may be withdrawn from the carburetor, inspected, adjusted so that the fuel valve will open at the desired degree of vacuum, and replaced as a unit in the carburetor without disturbing the adjustment. In order to increase the initial stress of spring 90, and thereby decrease the degree of vacuum required to seat the retaining member 1li, the plug 98 may be driven downwardly without disassembling the economizer unit. In order to decrease the initial stress of spring 90, the plug 88 may be unscrewed and the plug 98 driven in the opposite direction.

Although the invention has been described with reference to two specific embodiments thereof, it may be embodied in other forms within the skill of artisans in this art, and is not limited except in accordance with the terms of the following claims.

I claim:

1. In an economizer device for an internal combustion engine carburetor, a casing, a fuel passage and a vacuum chamber in said casing, a partition having an opening and provided in said casing to separate said fuel passage from said vacuum chamber, an economizer valve controlling said fuel passage and including a mov-- able member, a vacuum controlled plunger connected to said movable member and movable through the opening in said partition, and a washer forme-:l oi elastomer and embracing said plunger adjacent said opening in said partition to prevent leakage therethrough when the economizer valve is fully open.

2. The invention dened in claim 1 with said washer serving also to limit the movement of the plunger in the opening direction of the economizer valve.

3. The invention dened in claim l, with said n movable member including an elastomer controlled by said plunger and movable thereby into its open position, and a spring moving said elastomer to a seated position constituting the closed position of the economizer valve.

4. An economizer device for a carburetor having a fuel reservoir and a fuel conduit leading therefrom provided with a calibrated orifice, said device comprising a body designed to seat in an aperture in the reservoir and to project into the r interior thereof, said body being provided with a fuel passage by-passing said oriice, a valve seat formed on said body in the reservoir projecting end thereof to control said passage, an economizer valve unit adapted to cooperate with said seat to open and to close said fuel passage,

lil

a chamber having a movable Wall responsive to varying pressure in the chamber, a sealing valve seat provided between said passage and said chamber to separate the latter from said passage, a plunger connected to said movable wall to be moved thereby, said plunger being adapted to move said economizer valve unit to open said passage and spring means adapted to hold the economizer valve unit against said valve seat when the plunger is retracted, and a sealing valve unit including an annular member made of rubber-like material and adapted to be pressed against the seat provided between said passage and said chamber to seal the same when said economizer valve unit is fully open.

5. The invention defined in claim 4, the economizer valve unit including a sealing member made of a rubber-like material resistant to fuel and impurities thereof.

6. The invention dened in claim 4, said economizer valve unit including a metal member loosely slidable on the end of the plunger for a predetermined distance, said member carrying a sealing element made of a rubber-like material resistant to fuel and impurities thereof.

ROBERT H. HIEGER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 956,287 Champ Apr. 26, 1910 1,982,049 Fageol Nov. 27, 1934 2,135,539 Sinderson Nov. 8, 1938 2,136,959 Wineld Nov. 15, 1938 2,306,903 Ray Dec. 29, 1942 2,311,110 Johnson Feb. 16, 1943 2,313,258 Olson Mar. 9, 1943 2,537,347 Hieger et al Jan. 9, 1951 2,563,096 Bicknell Aug. 7, 1951 

